Ask HN: How to talk to my employer about side projects and IP?

Hi HN,

I work in software development at a large retail company and would like to pursue a side project that may one day evolve into a business of its own. Unfortunately, my employment contract says that my employer owns anything that I work on while in their employ. I'd like to pursue some kind of change in my employment agreement, so that I can work on this side project without worrying about potential complications if it ever becomes successful.

FWIW, my side project is a SAAS product that is unrelated to the core business of my employer and I don't think my employer would ever try to exercise its rights over my work. But I want to avoid any issues I might have if I try to bring on investors down the road or even sell the company.

How should I go about having this conversation with my employer?